Generic devices are well known in the state of the art and serve to separate solid impurities from liquids. These devices are especially used to clean municipal sewage or industrial sewage, where impurities (e.g. in form of stones or fibrous material) should be separated from a water fraction, in which case the separation performance depends, among other things, on the size of the filtering surface openings of the filtering drum.
In any case, during filtration, i.e., during the separation of the impurities, individual openings of the filtering surface are frequently clogged, so that they have to be cleaned from time to time or even continuously. This is done, for example, by spraying a cleaning liquid (which within the scope of the invention can be water or a filtering drum filtrate, for example). In this context, it is also known that the cleaning liquid is sprayed on the filtering surface with the help of one or several spray nozzles. Here, the spray nozzles are moved back and forth along a trajectory so they can spray all areas of the filtering surface with cleaning liquid.
Even if this type of cleaning already produces satisfactory cleaning results already, there is nonetheless a need to improve cleaning performance and with it, also the filtering performance of the device that will be used.
The task of the present invention is therefore to suggest a cleaning process for the corresponding devices that differs in this regard in a positive way from the known state of the art.